"He's a bundle of emotions," Todd Christie said from the convention floor. "Obviously, my dad is thinking a lot about my mom and wishes she was here. We are choosing our words carefully, not to get him worked up and start crying."

During his town halls, Chris Christie often repeats the same story about his mother and his last words to her.

Todd Christie said if his mother was alive today to see his brother give the keynote address, she would be as nervous as her father.

"She would be an unmitigated mess," Todd Christie said. She would have been a bundle of nerves, she wouldn't have eaten for two days, smoked a carton of cigarettes and drank a gallon of coffee."

Todd Christie said his father, the governor's wife and children will be sitting in Mitt Romney's box to watch the speech.

For him, the speech will be emotional.

"It's another in a series of surreal moments," Todd Christie said. "Just imagine if it's your brother, sharing conversations about what you want to do with your life. I am proud of him."